{"id":31183,"date":"2018-10-29T17:52:40","date_gmt":"2018-10-29T17:52:40","guid":{"rendered":"\/forum\/forums\/topic\/verification-of-tan-delta-for-viscoelastic-material\/"},"modified":"2018-10-29T17:52:40","modified_gmt":"2018-10-29T17:52:40","slug":"verification-of-tan-delta-for-viscoelastic-material","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/verification-of-tan-delta-for-viscoelastic-material\/","title":{"rendered":"verification of tan delta for viscoelastic material"},"content":{"rendered":"

Hi, <\/p>\n

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I am trying to verify the tan delta of viscoelastic material in Workbench. The model is simply a 10x10x10 mm cube.  Transient structural is chosen. <\/p>\n

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For the part of Shear modulus and bulk modulus, I obtained the experimental data from DMA and import those data points into Engineering data. And I have already verified that if there is a constant stress, then a creep compliance curve is obtained which is matched with my experimental data of creep compliance.<\/p>\n

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For tan delta,<\/p>\n

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I measured the storage modulus vs freq curve from DMA and import those data into WB by APDL commands.<\/p>\n

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\"\"<\/p>\n

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Then I set my pressure as a kind of sinusoidal pressure upon the top surface. The function of pressure is as follow.<\/p>\n

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Pressure=-0.4*sin(6.28*time) if pressure<0<\/p>\n

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otherwise pressure=0.<\/p>\n

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Those data are imported by XML file. I am pretty sure the pressure is correct. Here is the screenshot.<\/p>\n

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\"\"<\/p>\n

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Other boundary condition is a fixed support at the bottom.<\/p>\n

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According to the definition of tan delta, delta is a lag phase angle between stress and strain if the input is a sinusoidal stress.<\/p>\n

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But I cannot see any phase lag in my results. <\/p>\n

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Can you give any suggestions? or maybe I made some conceptional mistakes? Should I do it under Harmonic analysis?<\/p>\n

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Thanks in advance.<\/p>\n

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 <\/p>\n","protected":false},"template":"","class_list":["post-31183","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["3355"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0","0","0","0","0"],"_btv_view_count":["772"],"_bbp_subscription":["237464"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["31183"],"_bbp_forum_id":["27791"],"_bbp_engagement":["159625","161776"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["78776"],"_bbp_last_active_id":["78776"],"_bbp_last_active_time":["2019-02-27 08:42:05"]},"test":"seventanapply"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/31183","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/31183\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=31183"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}